Having a set of tools available is like an instrument to a musician, but there's more than just knowing how to play this instrument. Without the knowledge on how to play to the notes, disharmonies will come out, and the result will look (sound) bad1. And just as a musician has more than one way to interpret a certain piece of music, the converter of a document has to decide by which stylistic means he arranges the given fragments.
The following list of keypoints is intended to ease the process of identifying points which need attention, and to aid in deciding on how to solve them.